Even Light Drinking Might Have Risks

Cancer risk tied to alcohol at light and moderate levels for male smokers and women

Light drinking is sometimes praised as a heart-healthy habit, among other potential health benefits. But new evidence suggests it may be a habit that comes with risks.

A new study found that even light to moderate drinking in male smokers and in women — whether they smoked or not — was tied to an increased risk of certain cancers.

The authors of this new study, led by Dr. Yin Cao, of the Harvard T.H. Chan School of Public Health in Boston, explained that heavy drinking has been tied to an increased risk of certain cancers, including female breast cancer, colorectal cancer and liver cancer. However, less is known about the relationship between lighter drinking and cancer.

To explore this topic, Dr. Cao and colleagues looked at data from two large studies of US adults, involving over 88,000 women and 47,000 men. Patients were followed for as long as 30 years in these studies.

When looking at drinking levels, these researchers considered having up to one standard alcoholic drink per day for women and up to two drinks per day for men to be light to moderate drinking.

Overall, Dr. Cao and team found that light to moderate drinking was tied to a very slight increase in the risk of any cancer. When looking at cancers known to be tied to alcohol, the risk was only increased among light to moderate male drinkers who had a history of ever smoking. Nonsmoking men who were light to moderate drinkers did not have an increased risk.

All women who drank light to moderate amounts of alcohol had an increased risk of alcohol-related cancers, Dr. Cao and team found.

These increased risks were low. For instance, women drinking around one drink a day had a 1.13 times higher risk of developing an alcohol-related cancer than those who didn't drink. However, these risk increases were considered significant. Dr. Cao and colleagues said further research is needed to better understand the issue.

In an editorial about this study, J. Rehm, PhD, of the Centre for Addiction and Mental Health in Toronto, wrote that these results might make some people rethink their drinking habits.

"... [P]eople with a family history of cancer, especially women with a family history of breast cancer, should consider reducing their alcohol intake to below recommended limits, or even abstaining altogether, given the now well-established link between moderate drinking and alcohol related cancers," Dr. Rehm wrote.

The study and editorial were published online Aug. 18 in The BMJ. The National Institutes of Health funded this research. The authors disclosed no conflicts of interest.